Jesus' comments pertain to the Spiritual rebirth. (John 3:5) Whereas, Paul is speaking about death and resurrection of the natural body. (1 Cor 15:44)
If being born is one of two conditions necessary to enter the kingdom of God. It begs the question, who are the unborn people running around that need to be informed they need to be born?
Keep in mind that human beings have no control over being born. But they do have control over being born again.
Jesus said unless a man is born AGAIN he can't see... (John 3:3)
Nicodemus asks how being born AGAIN is possible. (John 3:4)
Jesus' answer, be born of water and Spirit. (John 3:5)
Again, consider the fact that all detailed NT conversion accounts involve both water and Spirit. (Acts 2:38-41, 8:12-18, 9:17-18, 10:43-48, 19:1-6, 22:16)
If it doesn’t make sense to discuss the natural birth in John 3 then shouldn’t this verse have been left out.
”That which is born of the flesh is flesh; and that which is born of the Spirit is spirit.“
John 3:6 KJV
https://bible.com/bible/1/jhn.3.6.KJV
You can see the tie to 1 Corinthians 15 by the terminology used. You referenced Jesus in John 3:3 and being born again.
The same terminology is used here in 1 Peter:
”Blessed be the God and Father of our Lord Jesus Christ, which according to his abundant mercy hath
begotten us again unto a lively hope by the resurrection of Jesus Christ from the dead, to an inheritance incorruptible, and undefiled, and that fadeth not away, reserved in heaven for you,“
1 Peter 1:3-4 KJV
https://bible.com/bible/1/1pe.1.3-4.KJV
”being born again, not of corruptible seed, but of incorruptible, by the word of God, which liveth and abideth for ever.“
1 Peter 1:23 KJV
https://bible.com/bible/1/1pe.1.23.KJV
This passage from 1 Corinthians 15 also references the corruptible and incorruptible seed.
”For this corruptible must put on incorruption, and this mortal must put on immortality. So when this corruptible shall have put on incorruption, and this mortal shall have put on immortality, then shall be brought to pass the saying that is written, Death is swallowed up in victory. O death, where is thy sting? O grave, where is thy victory?“
1 Corinthians 15:53-55 KJV
https://bible.com/bible/1/1co.15.53-55.KJV
And again we have 1 John 5:1.
”Whosoever believeth that Jesus is the Christ is born of God: and every one that loveth him that begat loveth him also that is begotten of him.“
1 John 5:1 KJV
https://bible.com/bible/1/1jn.5.1.KJV
If this is true as it has to be then it is impossible for the water in John 3:5 to be referring to water baptism. The two verses would contradict each other in a way that cannot be reconciled. If 1 John 5:1 was written in a way that allowed being borne of God to happen in the future after water baptism then they could coexist and both be correct. However, 1 John 5:1 says that a person who believes is already born of God.